Being an ultra-geek, I created a speadsheet comparing the three vehicles we were looking at at the time. With my outrageously high estimate gas price of $2.00 a gallon as the average over ten years (hah! It exceeded that within 6 months of buying the car!) I was due to hit the break-even point vs. one alternative at the 5 year point, vs. the second at the 7 year point. The car is now 5 years old, and by my spreadsheet's calculations, I have already broken even against both. Sometime around the 150,000-mile mark, it will even have paid off compared to just keeping the SUV it replaced.
As for the battery, there are many reports of Priuses (Prii?) going strong on their original battery pack at the 200,000 mile mark. You get slightly worse gas mileage, (40 vs. 45 MPG) because the battery can't hold as much charge, but you still do much better than a conventional car. (A taxi company in Vancouver, BC, has used Priuses since 2001; and got over 330,000 km (205,000 miles) before he replaced it with a newer model; and it was running just fine. Another taxi company in BC used a 2001 Prius for over 435,000 km (270,000 miles,) before retiring it without needing a battery replacement. I may drive more miles than average (my five-year-old car has almost 80,000 miles,) but I'm nowhere near the wear-and-tear these cars experienced. (And a cab's stop-and-go usage is even harder on the battery than my mostly-highway miles.)
The Prius is a little bigger than the Corolla, enough that it was the smallest car (interior passenger room-wise) we were looking at. The Corolla was just too small. Had the Camry Hybrid been around when we bought ours, we probably would have gotten that. (Or even the Accord Hybrid, which wasn't very impressive...)
Modern CFLs are great, the early ones (1998/1999) were horrendous. They all claimed a five-plus-year life, yet every single one I bought in '98/99 died within one year. Most of their replacements lasted barely a year as well. And, of course, back then, they were more like 10x as expensive.